We will test the effectiveness of an early integrated case management and ergonomics intervention to reduce work loss and costs resulting from work-related musculoskeletal disorders (WMSD). We will test this intervention with a randomized, controlled clinical trial enrolling 350 injured workers from two groups: hospital workers and employees of a major airline. WMSD affect an estimated 19 million persons per year in the United States and account for the majority of workers' compensation costs. Our study will test traditional medical care versus multi- disciplinary case management approach to the treatment of WMSD which includes individual ergonomic evaluation and worksite modifications for injured workers. Our proposed intervention is novel in three important ways: it will be instituted very early in the course of time loss injuries (at five days of lost work), it will routinely incorporate ergonomic workplace evaluations and job modifications, and it will incorporate elements of a disease state management model emphasizing coordinated, comprehensive care across a spectrum of injury severity. Although ergonomic interventions have proven valuable in primary prevention, there are few data available on role of worksite evaluation and modification for workers who are already injured. We hypothesize that a more comprehensive model of care delivery which includes worksite modifications will hasten safe return to work in addition to examining the effect of the intervention on duration of time loss, we will evaluate its effects on workers' compensation costs. We will also evaluate whether the intervention alters satisfaction with care among patients, physicians, and employers.